ABSTRACT COPD affects more than 5 percent of the population and is the third most common cause of death in the United States.1 Unfortunately, no cure for COPD exists and therapy includes either symptomatic control or surgical intervention. Although lung transplantation offers the potential to improve quality of life, 2, 3 controversy exists as to whether lung transplantation in persons with COPD confers a survival benefit compared to medical treatment alone.4-7 As no single medical answer exists, the patient's personal values and preferences regarding their disease and treatment options play an important role in the decision-making process regarding lung transplantation. This decision is complex and informed decision making may be difficult for patients with low health literacy. The goal of this proposal is to develop a health-literacy sensitive decision aid that helps patients with COPD understand their treatment options and helps clarify their preferences and values regarding the choice between medical management and lung transplantation. Iterative design and usability testing of a low fidelity prototype will be conducted in patients who have previously made the decision to be listed for lung transplantation to develop a formal web-based decision aid. Patients with low health literacy will be oversampled and a user-centered approach will be employed to ensure a clear representation of the needs of patients with low health literacy. Next, usability and acceptability of a web-based decision aid will be assessed by applying similar methods with potential lung transplant candidates. Feasibility of implementing the health literacy-sensitive decision aid among patients with advanced COPD will be elucidated. The impact of the decision aid on individuals': 1) knowledge and risk perceptions, 2) clarity about values, and 3) decisional self- efficacy will be assessed. The results of the project will inform a multicenter randomized control trial of decision aid implementation. The use of human computer interaction methods in a population of users who are oversampled (at least 50%) for low health literacy may serve as a process map for the development of future health literacy-sensitive decision aids.